The present invention relates to a novel catalyst and process for the catalytic vapor phase ammoxidation of olefins to nitriles using antimonate catalysts.
U.S. Pat. No. 3,716,496 discloses a catalyst useful for the ammoxidation of olefins to nitriles having the formula EQU Fe.sub.10 Sb.sub.20-60 Me.sub.0.01-1 Te.sub.0.05-5 Q.sub.0.1-20 O.sub.x
wherein
Me is an element selected from the group consisting of V, Mo and W and PA1 Q is an element selected from the group consisting of Cu, Ag, Be, Mg, Ca, Sr, Ba, Zn, Cd, La, Ce and Al. PA1 A is Cu, Ce, V, Cr and/or Mn; PA1 B is alkali metal, earth alkali, Co, Ni, Zn, Cd, rare earth metal other than Ce, Ga, In, Tl and/or Th; PA1 C is Mo, W, Nb, Ta, Sn, Ge, Ti, Zr, P, B and/or As; and PA1 a is 0.01 to 20; PA1 b is 0 to 20; PA1 c is 0.01 to 20; PA1 x is a number determined by the oxygen requirements of the other elements present; and PA1 A is Cu, Ce, V, Cr and/or or Mn; PA1 B is alkali metal, earth alkali, Co, Ni, Zn, Cd, rare earth metal other than Ce, Ga, Zn, Tl and/or Th; PA1 C is Mo, W, Nb, Ta, Sn, Ge, Ti, Zr, P, B and/or As; and PA1 a is 0.01 to 20; PA1 b is 0 to 20; PA1 c is 0.01 to 20; PA1 x is the number determined by the oxygen requirement of the other elements present; and
Netherlands Pat. No. 7,501,472 discloses similar catalysts, these catalysts also containing at least one of P and B.
In commercial vapor phase processes for producing acrylonitrile, a liquid reaction product containing acrolein, acrylic acid and acetonitrile as well as acrylonitrile is normally obtained. It is oftentimes difficult to separate acrolein, acrylic acid and/or acetonitrile from this liquid reaction product, and hence processes yielding these unwanted liquid byproducts in significant amounts are disadvantageous commercially. Unfortunately, vapor phase ammoxidation processes using promoted Fe-Te-Sb-O.sub.x catalysts do yield these unwanted byproducts in significant amounts. Furthermore, tellurium in such catalysts tends to volatilize as tellurium oxide, which leads not only to a significant decrease in catalytic activity with time but also to significant pollution problems.
Accordingly, it is an object of the present invention to provide a novel process for the ammoxidation of olefins to nitriles in which the production of acrolein, acrylic acid and acetonitrile is significantly reduced by means of a catalyst not containing tellurium as an essential component.